S-92908A313 0.125" ID x 0.438" OD Finishing Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide Steel finish, ideal for harsh industrial environments
• Precise 100° countersink angle ensures flush mounting and eliminates protrusion for smooth surfaces
• Optimized dimensional accuracy with 0.125" ID and 0.438" OD for perfect fit with No. 4 screws
• Exceptional durability backed by Rockwell 15N80 hardness for long-term performance under load
• Comprehensive compliance with RoHS 3 and REACH regulations for safe, sustainable industrial use
• Reliable load distribution with consistent 0.084-0.104" thickness to prevent surface damage
• Seamless integration into inch-based assembly systems for streamlined manufacturing processes

Professional Applications & Engineering Value

These 100° countersunk washers are engineered to solve critical industrial challenges where flush surface mounting and corrosion resistance are paramount. The Black-Oxide Steel construction provides a protective barrier against moisture and chemicals, significantly extending service life in demanding applications like automotive assemblies, machinery frames, and outdoor equipment. The precise 100° countersink angle perfectly matches standard screw heads, eliminating gaps and reducing stress concentration points. With a 0.125" ID and 0.438" OD, these washers ensure optimal load distribution for No. 4 screw installations, preventing material deformation and maintaining structural integrity in high-vibration environments. This combination of material strength and dimensional precision delivers reliable performance in aerospace, construction, and heavy machinery sectors where failure is not an option.

Specification Summary & Compliance

This washer features inch system dimensions with 0.125" internal diameter and 0.438" outer diameter, designed specifically for No. 4 screw size applications. The 100° countersink angle conforms to standard industrial specifications for flush mounting requirements. Material hardness is certified at Rockwell 15N80 for consistent performance. The product is fully compliant with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as an alloying element in steel and meets REACH (EC 1907/2006) requirements as of January 17, 2023, including 233 SVHC substances, ensuring regulatory adherence for global industrial markets.